At the same time, she's drawn indignation from a contingent of her own staff. After she ordered immigration agents to focus on high-priority cases in 2011, agents revolted. Union leaders for U.S. Immigration and Customs Enforcement (ICE) sued Napolitano in August 2012, claiming that she was violating the Constitution and federal law by telling them to ignore some undocumented immigrants.

Despite the ire from both extremes of the immigration debate, Napolitano typically remains in the background. President Barack Obama has taken the credit -- and scorn -- for both increased deportations and landmark immigration programs like deferred action. The program, which allowed more than 150,000 young undocumented people to live and work in the U.S. since it was enacted last summer, was signed into action by Napolitano.

Still, the Homeland Security secretary's record will face scrutiny next week, when she testifies before the Senate Judiciary Committee on immigration reform. Even with the avalanche of attention that will follow the State of the Union address the day before, she will likely be under the biggest spotlight since assuming her position in 2009.

Napolitano has arguably done more than any other administration official to shape Obama's image on immigration. As the head of the Department of Homeland Security (DHS), she oversees the agencies charged with protecting the border, regulating the flow of trade and combating illegal immigration. She led DHS to 1.6 million deportations during Obama's first term -- a record pace -- while increasingly prioritizing criminal removals.

That's helped shape the administration's case for immigration reform. The president routinely cites the record number of "boots on the ground" along the nation's borders to emphasize how the U.S. is prepared to combat future illegal immigration.

DHS and the secretary have also made it clear that they've wanted to put their energy into priority removals, which means a focus on the criminal population.
In a June 2011 memo, ICE Director John Morton ordered agents to exercise "prosecutorial discretion," telling them to determine whether a case was potentially low priority and hence not the best use of agency resources. Two months later, Napolitano issued a review of more than 411,000 backlogged deportation cases for possible dismissal. The review was the first of its kind, but The New York Times reported that as of June 2012, fewer than 2 percent of those cases had been closed.

President Obama also touts an increased focus on criminal removals during his tenure, as illustrated by a comment he made during a November presidential debate:

"[I]f we're going to go after folks who are here illegally, we should do it smartly and go after folks who are criminals, gang bangers, people who are hurting the community, not after students, not after folks who are here just because they're trying to figure out how to feed their families," he said. "And that's what we've done."

This message, while helpful to the president in promoting his immigration record, isn't entirely accurate. His administration has heaped up record deportations, but the vast majority aren't what most would consider "gang bangers," according to ICE statistics on removals.

Of the 396,906 removals by ICE in the 2011 fiscal year, 45 percent were non-criminal and 24 percent were for misdemeanors, what ICE calls Level 3 crimes. That means that 69 percent of the agency's deportations were of non-criminals or low-level offenders.

That year, 12 percent were for what ICE defines as Level 2 crimes, a mix of misdemeanors and felonies, including burglary, larceny and minor drug offenses. The most serious crimes, Level 1, represented 19 percent of removals. That includes crimes like major drug offenses, rape, murder and kidnapping.

ICE did not provide a detailed breakdown of the criminal charges at the time of this publication, but it's important to note that immigration crimes, like attempting to enter the country illegally, can be misdemeanors and felonies, and count toward the tally of criminal deportations.

A broader set of statistics looking at removals in that same year by both ICE and Customs and Border Protection (CBP) shows that 23 percent of removals were for drug crimes, 23 percent for criminal traffic offenses and 20 percent for immigration offenses. Those tallies mix misdemeanor and felony crimes.

The message that Obama has prioritized serious criminals rings hollow for some grassroots immigrant rights groups, who criticized him for sticking with Napolitano in his second term. On one hand, the president is pitching an immigration reform plan that would create a pathway to citizenship for law-abiding undocumented immigrants. On the other, he's deporting many people who might qualify for such a plan if it became law.

"We're not happy about it, we think it's a failed opportunity for the president to separate himself from his last four years," said Sarahi Uribe, the national campaign coordinator for the National Day Laborer Organizing Network (NDLON). "So far, Janet Napolitano has terrorized our communities through the record number of deportations that DHS has pursued...we were hoping he would have gone with someone who had a record of pro-immigrant policies and pro-worker policies."

In some past instances, the president has amended policy to follow his beliefs. In February 2011, he told the Justice Department to stop defending the Defense of Marriage Act, a federal law that prohibits same-sex marriage, on the grounds that it was unconstitutional. After Congress failed to pass a bill that would have created a path to citizenship for certain undocumented young people, he enacted Deferred Action for Childhood Arrivals in June of the following year to give DREAMers a way to live and work in the U.S.

Some will say that the mix of strong enforcement and pro-migrant programs like deferred action have created the political space to allow the immigration reform debate to move forward, and that halting deportations now could derail negotiations. "If you want to end deportation, the way to do it is to pass comprehensive immigration reform," said Simon Rosenberg, the president and founder of NDN, a progressive think tank and advocacy group. "There is a limit to what can be done administratively, but, frankly, I think they've pushed the envelope pretty hard."

Republican Sen. Marco Rubio, a key player in the Senate negotiations over immigration reform, has already said that President Obama "poisoned the well" for Republicans to engage on the issue when he started deferred action last summer. If he and Napolitano halted deportations now -- even for non-criminals -- Republicans working on reform might scatter.

To illustrate the tightrope that the administration is walking, look back to when Napolitano was reappointed as DHS chief last month. While some immigrant rights groups balked, others -- especially those inside the Beltway, more closely connected to reform negotiations -- lauded her return.

"I think with Secretary Napolitano as the head of the Department of Homeland Security, it certainly is very hard to argue that the Obama administration isn't serious about enforcement. She has been very aggressive in enforcing the law," Benjamin Johnson, the executive director of the American Immigration Council, told ABC/Univision. "She's bringing a lot of credibility and a lot of experience in making the case that we've done enforcement, and it's time to start thinking about other areas of immigration policy that have to be changed."

There are some D.C. advocates who don't think Obama needs Napolitano -- or the record deportations -- to make the case for immigration reform. The increasingly diverse electorate, particularly the Latino block, wants reform, and Republicans would be foolish to miss the opportunity, according to Frank Sharry, the executive director of America's Voice, a group that lobbies for immigration reform.

"I think that six, seven years ago, the argument that being tough on enforcement would create political space for reform, it may have had some legitimacy back in the day," he said. "And I would give this administration credit for its border security strategy. But I think it's interior enforcement strategy has been a human and political disaster."

This story was updated on Feb. 8, 2013, to reflect Secretary Napolitano's signing off on Deferred Action for Childhood Arrivals and her stance on priority removals.